This book will address three primary metals and their associated metals. The primary metals are Platinum Group of Elements or Metals (PGE or PGM), nickel, and chromium. The associated metals include copper, gold, silver, and cobalt. The platinum group consists of six metals and occurs naturally in close association with one another as well as with nickel, chromium, copper, and cobalt. The group of metals represents a unique geological process having a common source of metal supply and a genetic model. The PGM is among the least abundant group of elements of the Earth’s element family.

Teresa Valente Editorial for Special Issue “Pollutants in Acid Mine Drainage” Reprinted from

Darrell Kirk Nordstrom Geochemical Modeling of Iron and Aluminum Precipitation during Mixing and Neutralization of Acid Mine Drainage
Cl ´ementine Drapeau, Rabei Argane, C ´ecile Delolme, Denise Blanc, Mostafa Benzaazoua and Rachid Hakkou et al. Lead Mobilization and Speciation in Mining Waste: Experiments and Modeling
Elliott K. Skierszkan, John W. Dockrey, K. Ulrich Mayer, Viorica F. Bondici, Joyce M. McBeth and Roger D. Beckie Geochemical Controls on Uranium Release from Neutral-pH Rock Drainage Produced by Weathering of Granite, Gneiss, and Schist
Mariana Lemos, Teresa Valente, Paula Marinho Reis, Rita Fonseca, Itamar Delbem and Juliana Ventura et al. Mineralogical and Geochemical Characterization of Gold Mining Tailings and Their Potential to Generate Acid Mine Drainage (Minas Gerais, Brazil)

Sandstone reservoirs are the host for almost 60 percent of the world’s oil and gas reserves, and an understanding of the factors that determine the location and distribution of reservoir-quality sandstones is essential for any successful exploration and exploitation program.

The assessment of porphyry copper deposits in eastern Asia has a long history, and many people have been involved. USGS colleagues Klaus J. Schulz and Joseph A. Briskey initiated the project and participated in the first workshop, in Kunming, Yunnan, in 2002. Stephen G. Peters and Warren Nokleberg coordinated and led the initial assessment activities, prepared preliminary reports, and represented the USGS to our Chinese counterparts at several meetings.